Intrinsic self-healing polymers with a high E -modulus based on dynamic reversible urea bonds
Intrinsic self-healing polymers with a high E -modulus based on dynamic reversible urea bonds
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DOI：
10.1038/am.2017.125
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发表时间：
2017-08
影响因子：
9.7
通讯作者：
S. Zechel;R. Geitner;M. Abend;M. Siegmann;Marcel Enke;Natascha Kuhl;Moritz Klein;J. Vitz;S. Gr
中科院分区：
文献类型：
--
作者：
S. Zechel;R. Geitner;M. Abend;M. Siegmann;Marcel Enke;Natascha Kuhl;Moritz Klein;J. Vitz;S. Gr
提出了脲聚合物网络的直接合成。可商购的单体使用光诱导聚合进行聚合，产生通过受阻脲分子交联的网络。这些部分是可逆的，因此可以通过简单的热处理转化为起始化合物（即异氰酸酯和胺）。使用差示扫描量热法以及拉曼和红外光谱法来监测该过程。此外，这些聚合物网络的自愈能力进行了研究，使用划痕愈合测试，以及批量愈合的调查，使用拉伸测试。所得材料具有高E模量，能够在高于70 ℃的温度下多次愈合划痕，并且它们的机械性能可以部分再生。潜在的愈合机制是基于可逆的开放的脲键和两个官能团之间的交换反应，这是从光谱分析证实。总之，这些新材料是一种新型的内在可愈合聚合物，并提供了迈向坚硬和可愈合聚合物的第一步。
The straightforward synthesis of a urea polymer network is presented. Commercially available monomers are polymerized using light-induced polymerization, resulting in networks crosslinked by hindered urea molecules. These moieties are reversible and, thus, can be converted into the starting compounds (that is, isocyanate and amine) by a simple thermal treatment. This process is monitored using differential scanning calorimetry as well as Raman and infrared spectroscopy. Furthermore, the self-healing ability of these polymer networks is investigated using scratch-healing tests as well as bulk-healing investigations using tensile testing. The resultant materials have a high E-modulus, are able to heal scratches at temperatures above 70 C multiple times and their mechanical properties can be partially regenerated. The underlying healing mechanism is based on the reversible opening of the urea bonds and exchange reactions between two functional groups, which were confirmed from a spectroscopic analysis. In summary, these new materials are a new type of intrinsically healable polymers and provide a first step toward hard and healable polymers.